Choose the PDF, choose a PNG or JPG signature image, pick the page number and corner (bottom-right by default), and click Sign PDF - the download has that image stamped on the chosen page.
Sign PDF (Add Signature)
Place a signature image onto a PDF page, right in the browser.
Places one signature image on one page at a fixed corner - does not draw freehand on the PDF, does not fill AcroForm signature fields, and does not cryptographically certify or lock the document.
The files are processed in this browser tab and are never uploaded to a server.
To draw a signature as a PNG first, use the signature pad tool; to stamp text on every page, use the watermark tool.
How the signature is sized and placed
Sign PDF (Add Signature) does not stamp your image at its original pixel size. The width is capped at whichever is smaller: 180 points (about 2.5in), or 35% of the target page's own width - and the height scales by that same ratio, so the shape is never stretched or squashed. On a standard US Letter page (8.5in / 612pt wide), the 35% rule alone would allow about 2.97in, but the smaller 180-point cap wins, so the signature tops out at 2.5in wide there. On a narrower page - a half-size document at 5.5in / 396pt wide, for example - 35% of the width works out to about 1.9in, which is smaller than the 180-point cap, so the narrower page's own width becomes the limit instead. A signature that is already smaller than whichever cap applies is placed at its own native size; the tool only ever shrinks an oversized image, it never enlarges a small one. Whichever corner you pick - bottom right (the default), bottom left, top right, or top left - the image sits a fixed 24-point margin in from that corner's edges, so it never touches the page boundary.
Sign PDF vs. Signature Maker vs. Add Watermark to PDF
These three tools sound similar but do different jobs, and picking the wrong one wastes a round trip:
| Tool | Input | What it stamps, and where |
|---|---|---|
| Sign PDF (this tool) | An existing PDF + a PNG/JPG signature image you already have | That image on ONE page you choose, at one of four fixed corners |
| Signature Maker | A freehand mouse/touch/pointer drawing | Nothing on a PDF - it downloads the drawing itself as a PNG (opaque white or transparent background) |
| Add Watermark to PDF | Typed text, not an image | The SAME text on EVERY page, diagonal, gray, semi-transparent |
In short: use Signature Maker first if you need to create the signature image itself; use this tool once you already have a signature image and want it on one specific page; use Add Watermark to PDF instead when the goal is marking a whole document (for example "DRAFT") rather than adding a personal signature.
Frequently Asked Questions
What does Sign PDF (Add Signature) do?
Place a signature image onto a PDF page, right in the browser.
When should I reach for sign pdf (add signature)?
Places one signature image on one page at a fixed corner - does not draw freehand on the PDF, does not fill AcroForm signature fields, and does not cryptographically certify or lock the document.
What complementary tools work well alongside sign pdf (add signature)?
To draw a signature as a PNG first, use the signature pad tool; to stamp text on every page, use the watermark tool.
What happens if I choose a page number that doesn't exist in my PDF?
After you choose the PDF, the tool reads its real page count and limits the page-number field to that many pages. If you still enter a page beyond that count, clicking Sign PDF stops and shows the PDF's actual page count instead of guessing or placing the signature on the wrong page.
Does my signature image's file extension have to match its real format?
Not exactly. The tool first guesses PNG or JPG from the file's name and browser-reported type, but if that guess turns out wrong - for example a JPEG photo saved with a .png extension - it automatically retries the other image format before giving up, so a mislabeled signature file usually signs correctly anyway.
Can I move or resize the signature after it's been placed?
No - the position (one of the four corners) and the size cap are both fixed at the moment you click Sign PDF. To change either, sign the original PDF again with a different corner choice, or resize/crop the signature image itself before you upload it.
Can I put my signature on more than one page in the same PDF?
Each run of the tool signs exactly one chosen page - there is no setting that repeats the same signature across several pages in a single pass. To sign a second page too, download the first result, then run it back through Sign PDF a second time with the new page number.